13509749 has 4 divisors (see below), whose sum is σ = 14737920. Its totient is φ = 12281580.

The previous prime is 13509689. The next prime is 13509757. The reversal of 13509749 is 94790531.

It is a happy number.

13509749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13509749 is a prime.

It is a super-4 number, since 4×13509749⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13509649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 614069 + ... + 614090.

It is an arithmetic number, because the mean of its divisors is an integer number (3684480).

Almost surely, 2^13509749 is an apocalyptic number.

It is an amenable number.

13509749 is a deficient number, since it is larger than the sum of its proper divisors (1228171).

13509749 is a wasteful number, since it uses less digits than its factorization.

13509749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228170.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 13509749 is about 3675.5610456092. The cubic root of 13509749 is about 238.1674609402.

The spelling of 13509749 in words is "thirteen million, five hundred nine thousand, seven hundred forty-nine".